Palletized loading systems are known in which self-contained flatracks loaded with palletized cargo are moved from a position on the ground onto a truck by means of a hydraulic arm, hoist or crane 18 which may be mounted on the truck. When it is desired for the load capacity to be increased, the truck can be fitted to pull a trailer which can accommodate a second flatrack.
In order to load a flatrack onto a palletized loading system trailer, it must first be loaded onto the truck. Then the truck is backed up to the forward end of the trailer, and the flatrack is transferred rear end first onto the trailer. The truck then drives off and picks up a second flatrack, returns to attach the trailer, and the truck moves off with both loads.
Conversely, when unloading, the trailer is detached, the truck is unloaded, the trailer load is transferred onto the truck, and the second load unloaded onto the ground. It can be seen that in circumstances such as military operations where military hardware or medical supplies are being delivered to the filed, speedy and efficient loading and unloading of cargo are a necessity.
Existing systems for moving a flatrack from a truck to a trailer and securing it to the trailer utilize roller load-bearing surfaces and ISO corner castings with twist-lock pins. This design has not proved to be acceptable, as the rollers tend to "freeze up" under heavy loads and easily become jammed with rocks and debris out in the field. Further, the corner-casting "lock-in" mechanism requires that holes in the four corners of the flatrack line up with holes in the trailer frame to accept twist-lock pins. Alignment does not always occur on first loading, especially on uneven ground, necessitating re-lifting and realigning the load. Existing designs also require heavy outrigger beams extending perpendicularly from the main frame beams of the trailer, which add weight and cost to the trailer, and also require manual insertion of twist pins at four separate points.